Similar to Bug 1675128, this bug tracks the work to convert rest of the members in ReflowInput to store in logical coordinates.
https://searchfox.org/mozilla-central/rev/4415bec7a49c50a338167d9c8934527b9cae59d0/layout/generic/ReflowInput.h#452-493,499-506

I put the private member section at the end of ReflowInput's
declarations. In later patches, other members are going to live there
when they're converted to logical coordinates.

Remove unused AvailableWidth() and AvailableHeight() that return
writable-references.

I didn't port the comment section verbatim, but revise them according to
the best of my knowledge.

We can use them to implement SetComputedWidth() and SetComputedHeight()
rather than the other way around.

The logic involving whether to call InitResizeFlags() for viewport frame
can be simplified. That is, we don't want to call InitResizeFlags() for
viewport frame in SetComputedISize().

Remove unused ComputedWidth() and ComputedHeight() that return
writable-references.

Delete the comment describing that replaced frames should use their
intrinsic size if they have NS_UNCONSTRAINEDSIZE in mComputedWidth and
mComputedHeight, because we always have a definite size computed by
ComputeSizeWithIntrinsicDimensions().

Remove unused ComputedMinWidth(), ComputedMaxWidth(),
ComputedMinHeight(), and ComputedMaxHeight() that return
writable-references.

s/aContainingBlockSize/aCBSize/ for ComputeMinMaxValues() because that's
the parameter name used in definition.

https://hg.mozilla.org/mozilla-central/rev/bab2af0beed8
https://hg.mozilla.org/mozilla-central/rev/f875e1fd1c37
https://hg.mozilla.org/mozilla-central/rev/27eae27154d2
https://hg.mozilla.org/mozilla-central/rev/80ed365889fc
https://hg.mozilla.org/mozilla-central/rev/4e0ba157c016